Water-dispersible sulfopolyesters incorporating polyalkylene glycol units are known. U.S. Pat. Nos. 3,374,874 and 3,779,993 disclose linear water-dispersible sulfopolyesters containing polyethylene glycol (PEG). The patents define polyethylene glycol as a compound having the formula: EQU H--(OCH.sub.2 CH.sub.2).sub.x --OH
where x is an integer from 2 to 20, which corresponds to a polyethylene glycol molecular weight range of 106 to 898 g/mole. The glycol component of U.S. Pat. Nos. 3,374,874 and 3,779,993 contains at least 15 mole percent of PEG based on 100 mole % of total glycol.
U.S. Pat. No. 4,233,196 discloses linear water-dispersible sulfopolyesters containing polyethylene glycol. The polyethylene glycol component is present in a molecular weight range of 106 to 22,018 g/mole. The glycol component of U.S. Pat. No. 4,233,196 contains at least 15 mole percent of PEG based on 100 mole % of total glycol.
Copolyester-ether compositions which contain higher order polyalkylene glycols have been disclosed in the area of thermoplastic elastomers. U.S. Pat. No. 4,665,153 discloses copolyester-ether compositions containing 5 to 12 mole % of higher order polyalkylene glycols, such as polypropylene glycol and polytetramethylene glycol, and 2.5 to 10 mole % of a difunctional sulfomonomer. However, the copolyester-ether compositions disclosed in U.S. Pat. No. 4,665,153 are not water-dispersible.
Accordingly, what is needed is a linear, water-dispersible sulfopolyester which utilizes higher order polyalkylene glycols.